<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

</head>
<body>
<div id="app"></div>
<script src="../js/react.development.js"></script>
<script src="../js/react-dom.development.js"></script>
<script src="../js/babel.min.js"></script>
<script type="text/babel">
    const getNum=()=>{
        console.log(this)
    }

    function Index(){
        return <h1 onClick={getNum}>Hello React!</h1>
    }

    ReactDOM.render(<Index/>,document.getElementById('app'))
</script>
</body>
</html>